The life of a jellyfish may seem like a real snooze, but until now biologists were never certain if the gelatinous blobs actually slept. Now it appears that at least one group of jellyfish needs its beauty sleep just like us.

Some species of upside-down jellyfish (Cassiopea) meet all of the criteria for entering a “sleeplike state,” a group of Caltech researchers...

Warming one end of a strip of platinum shuttles electrons around according to their spin, a quantum property that makes them behave as if they are twirling around. Known as the spin Nernst effect, the newly detected phenomenon was the only one in a cadre of related spin effects that hadn’t previously been spotted,...

Nearly 1 in 5 adolescents has suffered at least one concussion, a survey of teens finds. Of those, 5.5 percent of them reported two or more concussions diagnosed in their lifetimes, researchers report in the September 26 JAMA.

About 13,000 eighth-, 10th- and 12th-graders took part in the 2016 Monitoring the Future survey, an annual national survey of adolescent behavior and health given...

A Neandertal child whose partial skeleton dates to around 49,000 years ago grew at the same pace as children do today, with a couple of exceptions. Growth of the child’s spine and brain lagged, a new study finds.

It’s unclear, though, whether developmental slowing in those parts of the body applied only to Neandertals or to Stone Age Homo sapiens as well. If so, environmental conditions...

Frog brains get busy long before they’re fully formed. Just a day after fertilization, embryonic brains begin sending signals to far-off places in the body, helping oversee the layout of complex patterns of muscles and nerve fibers. And when the brain is missing, bodily chaos ensues, researchers report online September 25 in Nature Communications.

It’s hard not to compliment kids on certain things. When my little girls fancy themselves up in tutus, which is every single time we leave the house, people tell them how pretty they are. I know these folks’ intentions are good, but an abundance of compliments on clothes and looks sends messages I’d rather my girls didn’t absorb at ages 2 and 4. Or ever, for that matter.

For some poison dart frogs, gaining resistance to one of their own toxins came with a price.

The genetic change that gives one group of frogs immunity to a particularly lethal toxin also disrupts a key chemical messenger in the brain. But the frogs have managed to sidestep the potentially damaging side effect through other genetic tweaks, researchers report in the...

A genetic risk factor for Alzheimer’s disease is a double, make that triple, whammy.

In addition to speeding up the development of brain plaques associated with Alzheimer’s, a gene variant known as APOE4 also makes tau tangles — another signature of the disease — worse, researchers report online September 20 in Nature. APOE4 protein also ramps up brain inflammation that kills brain cells...

No one knows whether chronic marijuana smoking causes emotional troubles or is a symptom of them.... This dearth of evidence has a number of explanations: serious lingering reactions, if they exist, occur after prolonged use, rarely after a single dose; marijuana has no known medical use, unlike LSD, so scientists have had little reason to study the drug…. Also,...

Plate tectonics may have gotten a pretty early start in Earth’s history. Most estimates put the onset of when the large plates that make up the planet’s outer crust began shifting at around 3 billion years ago. But a new study in the Sept. 22 Science that analyzes titanium in continental rocks asserts that plate tectonics began 500 million years earlier.